House Republicans turned on themselves yesterday after a third straight loss of a GOP-held House seat in special elections this year left both parties contemplating widespread Democratic gains in November.

In huddles, closed-door meetings and hastily arranged conference calls, some Republicans demanded the head of their political chief, while others decried their leadership as out of touch with the political catastrophe they face.

GOP leaders sought yesterday to "re-brand" the party with a new slogan and renewed pledges of fiscal rectitude and limited government. But the slogan -- "The Change You Deserve" -- came under mocking fire, because it parallels Democratic presidential front-runner Barack Obama's "Change We Can Believe In" motto and it mirrors the advertising slogan for the antidepressant Effexor.

"What we've got is a deficiency in our message and a loss of confidence in the American people that we will do what we say we're going to do," conceded Rep. Tom Cole (Okla.), chairman of the National Republican Congressional Committee.

The losses of conservative House seats in Louisiana and Illinois this spring were explained away by many Republicans as setbacks in which they were hampered by bad candidates. But Tuesday's loss in northern Mississippi was devastating. The district had given President Bush 62 percent of its vote in 2004. To reverse its losing streak, the NRCC pumped $1.3 million from its depleted coffers into the race. Freedom's Watch, a conservative independent group, pitched in. Vice President Cheney appeared at a last-minute rally. Bush and Sen. John McCain, the presumptive Republican presidential nominee, lent their voices to automated phone calls imploring Republicans to vote for Southaven Mayor Charles G. "Greg" Davis.

Davis lost the contest by eight percentage points, a wider margin than in either of the two previous special-election defeats.

As soon as the results came in Tuesday evening, Democrats were already gloating, some even talking publicly of a filibuster-proof 60-seat majority in the Senate. Charlie Cook, a nonpartisan political analyst, scoffed at 60, but he said he now could see gains of as many as seven Senate seats and 15 to 25 in the House. Democrats now hold a 236 to 199 majority in the House, up from 203 seats they controlled two years ago, and Republicans face a flood of retirements in the chamber. Retirement announcements from Senate Republicans in Colorado, New Mexico and Virginia have created prime pickup opportunities for Democrats, who will not be defending any open seats in November.

Ted Stevens, the longest-serving Republican senator in history, has been badly damaged by scandals besetting his family and his party in Alaska, creating an unexpected opportunity for Democrats. Sen. John E. Sununu (N.H.) is defending a seat in a state where Democratic fortunes are on the rise, and other Republican senators -- including Susan Collins (Maine), Norm Coleman (Minn.) and Gordon Smith (Ore.) -- are seeking reelection in states leaning Democratic in a presidential election year. In total, 23 Republican-held Senate seats will be on the ballot this fall compared with 12 for Democrats.

Even Republican strategists were downcast about their prospects for the fall.

"These races were not in New Jersey or New England, where Republican erosion has taken place over the last decade. They were in the heart of the Bible Belt, the social conservative core of our coalition," Rep. Tom Davis (Va.) fretted in a 20-page memorandum given to House Republican leaders yesterday and provided to The Washington Post.

"Members and pundits, waiting for Democrats to fumble the ball so that soft Republicans and Independents will snap back to the GOP, fail to understand the deep seeded antipathy toward the President, the war, gas prices, the economy, foreclosures and, in some areas, the underlying cultural differences that continue to brand our party."

Republicans from across the ideological spectrum of their party said yesterday that they understand the need to change course. But they disagreed on what change is necessary.

Rep. Ric Keller (Fla.), routinely targeted by Democrats in his Orlando district, said that Republicans from swing districts need the latitude to seek more moderate solutions, to be "independent folks who are trying to solve problems."

Rep. Mike Pence (Ind.), however, said the GOP needs to be more true to its conservative grass roots.

"Until we convince our public we have renewed our commitment to limited government and fiscal discipline, we will continue to lose," he said.

Rep. Walter B. Jones (N.C.), who just crushed a primary opponent challenging him on his antiwar stance, said it is time to break with Bush and find a way out of Iraq.

"If this party does not look at options and figure out how to pursue those options, we're in real trouble," he said.

Several Republicans decried the NRCC's strategy in the Mississippi and Louisiana special elections of nationalizing the campaigns by linking the Democratic candidates to Obama. All that did, they said, was energize African Americans to vote, while taking the GOP's focus off the local issues the Democrats were riding to victory. "Cheap, partisan political points" are not going to work in this environment, Keller said.

At a tense closed-door meeting of the House Republican Conference, Cole took full responsibility for the string of losses. But in a hastily arranged conference call with reporters, he dismissed any call for his resignation or a staff shakeup, which some Republicans have suggested may be necessary.

"You have to get beyond campaign tactics and take a long, hard look if there's something wrong with your product," he said. "It would be a great mistake to think that this could be fixed by tweaking a few things or a staff thing."

And Cole rejected the notion of a dramatic break with Bush.

"I don't see it particularly as an advantage to be in a debate with our president," he said. "It's not for me to second-guess the president of the United States."

But the numbers point to some dramatic action. In recent days, two polls put Sen. Elizabeth Dole's Democratic challenger within striking distance of her in North Carolina. Another poll showed Democrats gaining on Smith, a moderate who appeared to be escaping the heat of the election year. Even Sen. John Cornyn, one of Bush's closest allies and a fellow Texan, may be feeling some heat from state Rep. Rick Noriega, a veteran of the war in Afghanistan.

"We haven't hit bottom yet. I've never seen members so frustrated or demoralized," former House majority leader Tom DeLay (Tex.) said in an interview.

DeLay and former House speaker Newt Gingrich (Ga.) have been issuing calls to arms to their former troops. But even they disagree on the steps needed to reverse their fortunes, with Gingrich demanding an emergency meeting of all Republicans to craft a new agenda. Gingrich is offering unusual proposals such as reforming the Census Bureau and the Federal Aviation Administration.

But DeLay called those ideas "a yawn" and instead demanded a dramatic agenda that would energize the conservative base -- or else face major losses in the fall leading to wholesale changes in leadership next year.

"That sort of thing will happen over time if there are more losses. You can never gauge when members have had enough," he said.

"There is no simple, easy way out of this," said Glen Bolger, a GOP pollster who works closely with congressional Republicans. "This is extraordinarily problematic."